This invention relates generally to a scanning type antenna system and more particularly to a conical scan antenna system which includes two separate feed assemblies for simultaneously operating in two different frequency ranges.
Previously, conical scan of a radar signal pattern, for example, has been accomplished by rotating or nutating the entire feed. A need was recognized for eliminating the rotating feed where broadband coverage utilizing multiple polarizations was required. In addition to the utilization of rotating prisms, parasitic elements that rotate about a stationary active feed have been utilized. An example of the latter type system is disclosed in U.S. Pat. No. 3,277,490, "Broadband Conical Scan Feed For Parabolic Antennas" issued to L. Williams on Oct. 4, 1966.
Accordingly, it is an object of the present invention to provide a new and improved conical scanning antenna system.
Another object of the present invention is to provide a new and improved conical scanning antenna system which includes both active and passive feeds for operating in two frequency bands simultaneously.
Still another object of the present invention is to provide a new and improved conical scanning antenna system wherein two separate feed assemblies utilize a common antenna element.